This isn't exactly a question about installing Zimbra so I'll move it to the correct forum.
There's no mention of it in a forum search so I guess not, you also don't say what 'JOSSO' is nor have you provided any information about it. Have you looked at preauth for doing what you need?
I'm sorry because posted this question in wrong forum, and thank you for moved it to the correct forum.
JOSSO is single sign on framework, it is something like CAS.
Thank you for your information/link about preauth, i'm looking at that.